Final answer:
Cooing is a one-syllable combination of consonant and vowel sounds made by babies, which reflects the tonal patterns of their home language and is an integral part of early language development.
Step-by-step explanation:
Cooing refers to a one-syllable combination of a consonant and a vowel sound, such as 'coo' or 'ba'. Specifically, it is part of early language development in babies and is distinct from other types of vocalizations like babbling. Cooing typically reflects the tonal patterns of the language the baby is exposed to at home.
For example, the cooing of a baby raised in a French-speaking household may sound different from that of a Spanish or Urdu-speaking household. As babies grow, this cooing evolves into babbling, and eventually, into meaningful word formation.